New long noncoding RNA biomarkers and ceRNA networks on miR-616-3p in colorectal cancer: Bioinformatics-based study.

Background: Cancer development is aided by the role of long noncoding RNAs (lncRNAs) that act as competing endogenous RNAs (ceRNAs) absorbing microRNAs (miRNAs). We aimed to discover a novel regulatory axis in colorectal cancer (CRC) and potential biomarkers based on miR-616-3p. Materials and Methods: The gene expression omnibus database was mined for differentially expressed lncRNAs (DELs) and mRNAs. LncRNAs and mRNAs were predicted using the RegRNA and TargetScan databases. A combination of the ciBioPortal and Ensemble databases was used to locate the mRNAs. Cytoscape 3.7.1-built CeRNA networks. A quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to confirm the expression levels of these RNA molecules. Statistical analyses were implemented by GraphPad Prism 9. Results: qRT-PCR showed (Linc01282, lnc-MYADM-1:1, and Zinc Finger Protein 347 [ZNF347]) were overexpressed whereas, (salt-inducible kinases 1 [SIK1], and miR-616-3p) were down regulated. Conclusion: These results identify unique, unreported lncRNAs as CRC prognostic biomarkers, as well as prospective mRNAs as new treatment targets and predictive biomarkers for CRC. In addition, our study uncovered unexplored ceRNA networks that should be studied further in CRC.

Constructing a novel competing Endogenous RNAs network based on NR3C1 and X-linked inhibitor of apoptosis protein genes reveals potential prognostic biomarkers in colorectal cancer.

Background: Long noncoding RNAs (lncRNAs) have been recognized as the main modulatory molecules in various cancers and perform as competing endogenous RNAs (ceRNAs). The nuclear hormone receptor superfamily of ligand-activated transcription factors (NR3C1) regulates numerous proliferative and metabolic processes such as tumorigenesis and metabolic diseases. Furthermore, X-linked inhibitor of apoptosis protein (XIAP) belongs to a family of the inhibitors of apoptosis proteins, is located downstream of the glucocorticoid receptor (GR or NR3C1) pathway, and cooperates with GR to suppress apoptosis. However, the underlying mechanisms of NR3C1 and XIAP in colorectal cancer (CRC) remain mainly unclear. This research aims to clarify the potential RNA biomarkers and to construct a novel ceRNA network in CRC. Materials and Methods: Multistep bioinformatics methods such as Lnc2cancer and miRDB databases were applied to identify candidate lncRNAs and miRNAs. The interaction energy between lncRNAs, NR3C1, and XIAP genes was analyzed by the LncRRIsearch database. Plus, microRNAs and lncRNA were evaluated via the Diana tools database to select microRNAs with the most binding scores. Quantitative reverse transcription-polymerase chain reaction (QRT-PCR) was applied to verify RNA molecules' expression levels and their association with the clinicopathological factors in 30 CRC tissues compared to 30 adjacent tissues. Results: QRT-PCR showed upregulation of KCNQ1OT1, NR3C1, and XIAP and downregulation of miR-421. The ceRNA network was constructed with 17 lncRNAs, 2 mRNAs, and 42 miRNAs. Thus, we explained the potential interactions between KCNQ1OT1 and miR-421 with NR3C1 and XIAP genes. Conclusion: Our study represents potential prognostic biomarkers and a new ceRNA network for further study in CRC.

Candida colonization of the esophagus and gastric mucosa; a comparison of patients taking proton pump inhibitors and those taking histamine receptor antagonist drugs.

AIM: Investigation of Candida colonization of the esophagus and gastric mucosa in patients taking proton pump inhibitors in comparison with those taking histamine-2 receptor antagonists. BACKGROUND: Candida species are normal flora of alimentary tract that can cause infection of the esophagus and gastro-intestinal tract in immunocompromised patients. Consumption of proton pump inhibitors and histamine-2 receptor antagonists has been shown to alter the gastric pH, which may predispose the esophagus and stomach to floral transmission and colonization. METHODS: Two hundred and forty-five clinical specimens were obtained from 91 patients who underwent endoscopy from September 2019 to February 2020. Direct microscopy with KOH 10% and subculture on sabouraud dextrose agar containing chloramphenicol was used as primary screening. PCR with ITS primers was performed to amplify the ITS1-5.8SrDNA-ITS2 region, and the MspI restriction enzyme was used for RFLP to identify clinical isolates. RESULTS: Seventy cultures out of 245 specimens were positive for Candida colonization (28.5%). Colonization of Candida species in gastric acid and gastric tissue biopsies of patients who took PPIs and H2 blockers was significantly higher than in those in the control group (p= 0.001). The use of ranitidine, pantoprazole, and omeprazole increased the risk of gastric candidiasis by 10.60, 9.20, and 12.99 times, respectively (p< 0.05). CONCLUSION: The use of PPIs and H2 blockers, ageing, and consumption of vegetables were main risk factors for gastric colonization in the present survey; other variables, such as Candida species, cigarette smoking, and alcohol consumption, were not implicated in the development of gastroesophageal lesions. Further investigations are necessary to understand how these predisposing factors change the host's defense mechanisms and increase colonization of fungi at mucosal surfaces.